Casey Kasem, the famed radio DJ who became known to animation fans everywhere as the voice of Shaggy on Scooby-Doo!, has passed away, Variety is reporting. The man behind America’s Top 40 also did a number of voices on Sesame Street, as well as the title character in Rankin/Bass’s often forgotten Easter special Here Comes Peter Cottontail. Movie fans may also remember hearing Kasem as “himself” in the classic comedy Ghostbusters. Kasem made headlines a few weeks ago when he suddenly went missing, but we now know that was due to a form of progressive dementia. He was 82 years old.